Methane is one of two primary gases produced from the decomposition of landfill waste. Studies have been directed to collection and mitigation of methane gas. In small landfills, collection is not an economically feasible solution. Bio-cover placement is an inexpensive approach to mitigating methane emissions. The enhancing of oxidation processes by placement of bio-covers will reduce emissions even while gas extraction is employed and improve aesthetic quality of solid waste facilities. The... Show moreMethane is one of two primary gases produced from the decomposition of landfill waste. Studies have been directed to collection and mitigation of methane gas. In small landfills, collection is not an economically feasible solution. Bio-cover placement is an inexpensive approach to mitigating methane emissions. The enhancing of oxidation processes by placement of bio-covers will reduce emissions even while gas extraction is employed and improve aesthetic quality of solid waste facilities. The overall objective of the research is to mitigate methane emissions from landfills. To reach this objective, a test site was selected to evaluate the effects of compost placement over a closed landfill. The static chamber technique was used to estimate methane emissions and the stable isotope tracing method was used to determine oxidation rates. Hot spots were identified in the grid area and emissions at these spots were analyzed more in detail. Results obtained during the first year of the study are presented in this thesis. In these investigative efforts, it was noted that moisture content plays a significant role in controlling emissions and oxidation. At high water contents, low flux emissions were measured observed and at low water contents, emissions were higher. Oxidation rates varied in much the same way. High water contents corresponded with low oxidation rates and vise versa. Further study on the effects of moisture content and other variables on flux emission and oxidation is warranted. Show less

Date Issued

2005

Identifier

FSU_migr_etd-0520

Format

Thesis

Title

Environmental Sustainability of Ethanol Production Using the Lifecycle Analysis Method.

Ethanol is a controversial source of alternative fuel. In the United States ethanol is produced predominantly from corn and has made headlines as a popular green energy, driven both politically and geographically. Green energy is defined as an energy that has little or no negative environmental impacts. The purpose of this study is to determine if ethanol is really a green energy. This determination can be made by quantifying the greenhouse gas emissions produced by ethanol production using... Show moreEthanol is a controversial source of alternative fuel. In the United States ethanol is produced predominantly from corn and has made headlines as a popular green energy, driven both politically and geographically. Green energy is defined as an energy that has little or no negative environmental impacts. The purpose of this study is to determine if ethanol is really a green energy. This determination can be made by quantifying the greenhouse gas emissions produced by ethanol production using the LCA (Life Cycle Assessment) method of analysis. Using equivalent units, carbon dioxide emissions can be quantified and compared to other sources of alternative energies. Carbon footprinting is mainly used to understand the impacts humans have individually and as a mass on the environment. It can be computed and expressed as a quantity towards the computation of greenhouse gas contribution. In the case of ethanol, a carbon footprint can be developed by looking at the physical life cycle of a kernel of corn, cane of sugar or bushel of switchgrass. Comprehensively, the ethanol life cycle can be divided into four main parameters. The first parameter is feedstock, followed by technology, third is capital and the final parameter is off take. While each parameter is singularly important, this study focuses on greenhouse gas emissions. It was determined that in comparison, corn ethanol greenhouse gas emissions far exceed the greenhouse gas emission of both sugarcane and switchgrass (cellulosic) ethanol for any case. In the case where LCA is carried through distribution and use of ethanol, sugarcane ethanol is the less greenhouse gas emissive. In the case where the LCA stops at ethanol production, switchgrass is the less greenhouse gas emissive. It is important to note, however, that switchgrass (cellulosic) ethanol is in its infancy as of this writing and data provided is largely projected on the part of the respective researcher. Show less

Date Issued

2008

Identifier

FSU_migr_etd-1287

Format

Thesis

Title

Evaluation and Enhancement of Electro-Kinetic Technology for Remediation of Chromium Copper Arsenic from Clayey Soil.

A relatively new technique of electro-kinetic remediation is examined to evaluate and enhance removal of residual of the CCA (chromated copper arsenate) from clayey soil. A short duration (25-hours) treatment approach was initiated for this purpose. Laboratory 1-D column tests were performed on kaolin soil under the influence of DC electric field. Different chemicals (acid, alkali and oxidizing agents) and tap water were purged through electro-osmotic flow to enhance chromium, copper, arsenic... Show moreA relatively new technique of electro-kinetic remediation is examined to evaluate and enhance removal of residual of the CCA (chromated copper arsenate) from clayey soil. A short duration (25-hours) treatment approach was initiated for this purpose. Laboratory 1-D column tests were performed on kaolin soil under the influence of DC electric field. Different chemicals (acid, alkali and oxidizing agents) and tap water were purged through electro-osmotic flow to enhance chromium, copper, arsenic remediation. Configuration of electrodes/reactor setup was also adjusted to improve the removal efficiency of the CCA chemicals by inducing buoyancy with electro-osmotic flow. Interesting results were obtained showing up to 78% of arsenic and 72% copper removal by purging sodium hypo-chlorite (NaOCl). Sodium hydroxide (NaOH) purging also indicated enhanced removal with 74% arsenic and 72% copper removal. It was difficult to remove chromium and maximum removal was only 3.75% when the soil was purged with tap water. The batch experiments show that with respect to individual contaminant remediation, the removal efficiency increases many times when contaminants in the soil are in mixed-form. Inclined reactor setup showed enhanced electro-osmotic flow due to the effect of buoyancy. A model combining main phenomena of contaminant movement: electro-migration, electro-osmosis, diffusion, and buoyancy was developed for a small Debye length. The model predicts the behavior of pH, which is an important parameter that governs the migration of contaminants. Calculation based on the model showed excellent agreement when compared with the pH profile of experimental data of tap water purging for copper remediation. Although additional modeling and experimentation is needed, the results of this thesis demonstrate that electro-kinetic remediation with suitable purging chemicals may offer enhanced removal of polluted soil. Show less

Date Issued

2004

Identifier

FSU_migr_etd-0018

Format

Thesis

Title

Physicochemical and Hydrodynamics Aspects of Electrokinetics in Soil Remediation: A Study Based on Fundamental Principles and Modeling Approaches.

The presence of contaminant sites on the earth's surface is quite common and the need for their cleaning is huge and urgent. From the many technology efforts made to avoid the spreading of contaminants such as heavy metals the application of an electrical field on a soil matrix has given encouraging results. Several reports have described the goodness of electrokinetic-remediation as follows: it can be applied in situ, no excavation is necessary, it targets specific contaminants, and it works... Show moreThe presence of contaminant sites on the earth's surface is quite common and the need for their cleaning is huge and urgent. From the many technology efforts made to avoid the spreading of contaminants such as heavy metals the application of an electrical field on a soil matrix has given encouraging results. Several reports have described the goodness of electrokinetic-remediation as follows: it can be applied in situ, no excavation is necessary, it targets specific contaminants, and it works in low permeability soils. In fact, these are the reasons why applying electrical fields has been one technology pathway that has received so much attention in recent years. Although electrokinetic soil remediation has remained a promising technology, the drawbacks in field tests have suggested that fundamental research is still needed to fully understand the process. In effect, the analysis of the porosity, in conjunction with a more realistic set of transport forces, i.e. electroosmosis, electromigration, buoyancy and advection, is still missing in the literature and therefore it is the subject matter of this research. Consequently, this work concentrates on the analysis and comparison of predictions of at least three main aspects of electroremediation, i.e., heat transfer, electrostatics, and hydrodynamics. Overall, the comparison of transport forces is based on the use of different geometrical models to bring the role of porous media aspect and electrode shape into the analysis. Additionally, a new solution strategy is proposed for the differential equations of the electrostatic potential based on the Debye-Hückel approximation. From the study, the collected information is useful to identify further efforts to be made in investigation and to delineate a systematic approach for a more rigorous description of the electroremediation process. Implications for design of devices and cleaning strategies are also included. The knowledge obtained in this analysis is useful to promote a deeper understanding of the behavior of the system, and to lead to important guidelines for improving cleaning efficiency in a given application. Show less